Hygienic behaviour in the Australian stingless bees Tetragonula carbonaria and T. hockingsi

Hygienic behaviour is a natural mechanism of colony-level disease resistance to brood pathogens and has been reported in honey bees and stingless bees. Workers displaying Hygienic behaviour detect, uncap and remove dead and/or pathogenic brood from brood cells.

A novel brood disease was recently confirmed in the Australian stingless bees Tetragonula carbonaria and Tetragonula hockingsi. Do these bees show hygienic behaviour in response to this disease? To address this, we investigated hygienic behaviour in eight colonies of T. carbonaria and four colonies of T. hockingsi, by observing the response of workers to brood killed by freezing-or stabbing. Hygienic behav-iour was present in both species and was rapidly ex-pressed in both assays. In T. carbonaria, the average time for removal of freeze-killed and pin-killed brood was 9 hours and 8 hours, respectively. In T. hockingsi, removal of freeze-killed and pin-killed brood was 14 hours and 10 hours, respectively. There was no signifi-cant difference (α = 0.05) in time taken to complete the hygienic behaviour phases (detection, uncapping, removal or cell dismantling) between assay type or assay order in both species. However, intercolony var-iation was observed in both species in the assays, suggesting that like honey bees, hygienic behaviour may have a genetic component. Tetragonula carbonaria and T. hockingsi displayed significantly faster detec-tion, uncapping, removal and cell dismantling times than any of the stingless bees or most honey bees studied previously. This may, in part, explain why stingless bees appear to suffer from relatively few brood diseases.

Citation: Kayla S. Le Gros, James C. Makinson & Rob-ert N. Spooner-Hart. Hygienic behaviour in the Aus-tralian stingless bees Tetragonula carbonaria and T. hockingsi. Journal of Apicultural Research 2022, V 61, 578–590, https://doi.org/10.1080/00218839.2022.2109915

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